Agreement and reliability of withers height measurement using a handheld laser distance meter and a conventional measuring stick in cattle

This study evaluated agreement and repeated-measurement reliability of a handheld laser distance meter for measuring withers height in cattle compared with a conventional measuring stick. Agreement was assessed in 121 cattle measured once with each method. Repeated-measurement reliability was evaluated in 59 cattle measured in three sessions at 3-day intervals, with three replicate measurements per method in each session and a different observer in each session. In the agreement experiment, the mean difference between methods was 0.52 cm, with 95% limits of agreement of -2.4 to 3.4 cm. In the repeated-measurement experiment, within-observer/session standard deviations were 0.64 cm for the measuring stick and 0.60 cm for the laser distance meter, with repeatability coefficients of 1.77 and 1.66 cm, respectively. Reproducibility coefficients across observer/sessions were 3.12 and 3.49 cm, respectively. Although a significant observer/session effect was detected (P < 0.001), the method × observer/session interaction was not significant (P = 0.228). These findings indicate close agreement between the two methods and similar within-observer/session repeatability, supporting the handheld laser distance meter as a practical alternative for measuring withers height in cattle.